Grand Duchy of Lithuania

The Grand Duchy of Lithuania (1251-1795) was a European state that encompassed present-day Lithuania, Estonia, Latvia, eastern Poland, and much of Ukraine and Belarus. With its capital at Vilnius, Lithuania was originally a pagan state that fought the Teutonic Order, and even after it converted to Christianity and allied with Catholic Poland, they fought against the knights and by 1521 evicted them. In 1569 Lithuania and Poland formed Poland-Lithuania, but in 1795 it became a part of the Russian Empire.

History
Founded by the polytheistic Lithuanian Baltic tribes, the Lithuanians were originally a forest-dwelling pagan people. In the early 1200s, the monastic Teutonic Order of crusading German knights fought in a series of crusades against the Lithuanians, Livonians, and Samogitians, but Lithuania proved that it could survive the onslaught in the 1236 Battle of Saule (Siauliai), destroying a Teutonic/Livonian army. They proceeded to resist the knights until Mindaugas, their king, converted to Christianity, when they allied with Catholic Poland. Together, they took the fight to the Teutonic Order, and by 1521 they conquered them.

In 1277, the Lithuanians fought a war with neighboring Novgorod, an Orthodox Christian Russian state. The Novgorodians conquered their lands in Belarus and Ukraine in a bloody war, causing a period of rivalry between Russia and the Lithuanians. This lasted into the early 1500s, when Ivan III of Russia ("Ivan the Great") conquered much of their territory in alliance with the Crimean Khanate. The Lithuanians eventually consolidated their position by joining Poland as Poland-Lithuania in 1569.

In the aftermath of the union, the King of Poland also held the title of Grand Duke of Lithuania. Poland-Lithuania lasted until 1795, when the Russian Empire partitioned Poland-Lithuania with Prussia and Austria. Russia gained the Baltic states, including Lithuania, and held them until 1918.